While American culture and business tend to be dominated by extroverts, business consultant Cain explores and champions the one-third to one-half of the population who are introverts. She defines the term broadly, including "solitude-seeking" and "contemplative," but also "sensitive," "humble," and "risk-averse." Such individuals, she claims (though with insufficient evidence), are "disproportionately represented among the ranks of the spectacularly creative." Yet the American school and workplace make it difficult for those who draw strength from solitary musing by over-emphasizing teamwork and what she calls "the new Groupthink." Cain gives excellent portraits of a number of introverts and shatters misconceptions. For example, she notes, introverts can negotiate as well as, or better than, alpha males and females because they can take a firm stand "without inflaming [their] counterpart's ego." Cain provides tips to parents and teachers of children who are introverted or seem socially awkward and isolated. She suggests, for instance, exposing them gradually to new experiences that are otherwise overstimulating. Cain consistently holds the reader's interest by presenting individual profiles, looking at places dominated by extroverts (Harvard Business School) and introverts (a West Coast retreat center), and reporting on the latest studies. Her diligence, research, and passion for this important topic has richly paid off. –Publishers Weekly